Effect of carburizing and hardening temperature on the endurance of forming dies from steel R6M5

Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 3, pp. 19 - 23, March, 2013

КРАУДФАНДИНГОВІ ТЕХНОЛОГІЇ У РОЗВИТКУ НАЦІОНАЛЬНОЇ ТУРИСТИЧНОЇ СИСТЕМИ

The article substantiates the sense of crowdfunding and determines a list of participants of crowdfunding projects. The author has proposed a scheme for implementation of a crowdfunding tourism project, indicating the main stakeholders. The author has substantiated directions of implementation of projects, using crowdfunding in the national tourism system. The author has suggested a “house” of crowdfunding for projects of the national tourism system. The article determines advantages and disadvantages of crowdfunding for the main stakeholders and the society.    В статье обоснована сущность краудфандинга и краудфандинговых технологий, определен круг их участников. Предложено процесс реализации краудфандинга туристического проекта с указанием основных стейкхолдеров. Обоснованы направления реализации проектов с помощью краудфандинга в туристической системе. Предложено «архитектонику» краудфандинга проектов национальной туристической системы. Определены преимущества и недостатки краудфандинга для основных стейкхолдеров и общества.У статті обґрунтовано сутність краудфандингу та краудфандингових технологій, визначено коло їх учасників. Запропоновано процес реалізації краудфандингу туристичного проекту із зазначенням основних стейкхолдерів. Обгрунтовані напрямами реалізації проектів за допомогою краудфандингу в туристичній системі. Запропоновано «архітектоніку» краудфандингу проектів національної туристичної системи. Визначено переваги та недоліки краудфандингу для основних стейкхолдерів та суспільства

Spin susceptibility in superconductors without inversion symmetry

In materials without spatial inversion symmetry the spin degeneracy of the conduction electrons can be lifted by an antisymmetric spin-orbit coupling. We discuss the influence of this spin-orbit coupling on the spin susceptibility of such superconductors, with a particular emphasis on the recently discovered heavy Fermion superconductor CePt3Si. We find that, for this compound (with tetragonal crystal symmetry,) irrespective of the pairing symmetry, the stable superconducting phases would give a very weak change of the spin susceptibility for fields along the c-axis and an intermediate reduction for fields in the basal plane. We also comment on the consequences for the paramagnetic limiting in this material.Comment: 10 pages, 3 figure

Joule Heating and Current-Induced Instabilities in Magnetic Nanocontacts

We consider the electrical current through a magnetic point contact in the limit of a strong inelastic scattering of electrons. In this limit local Joule heating of the contact region plays a decisive role in determining the transport properties of the point contact. We show that if an applied constant bias voltage exceeds a critical value, the stationary state of the system is unstable, and that periodic, non-harmonic oscillations in time of both the electrical current through the contact and the local temperature in the contact region develop spontaneously. Our estimations show that the necessary experimental conditions for observing such oscillations with characteristic frequencies in the range $10^8 \div 10^9$ Hz can easily be met. We also show a possibility to manipulate upon the magnetization direction of a magnetic grain coupled through a point contact to a bulk ferromagnetic by exciting the above-mentioned thermal-electric oscillations.Comment: 9 pages, 6 figures, submitted to Physical Review

Frictional drag between quantum wells mediated by fluctuating electromagnetic field

We use the theory of the fluctuating electromagnetic field to calculate the frictional drag between nearby two-and three dimensional electron systems. The frictional drag results from coupling via a fluctuating electromagnetic field, and can be considered as the dissipative part of the van der Waals interaction. In comparison with other similar calculations for semiconductor two-dimensional system we include retardation effects. We consider the dependence of the frictional drag force on the temperature $T$, electron density and separation $d$. We find, that retardation effects become dominating factor for high electron densities, corresponding thing metallic film, and suggest a new experiment to test the theory. The relation between friction and heat transfer is also briefly commented on.Comment: 14 pages, 4 figure

Search for double beta decay of 136^{136}Ce and 138^{138}Ce with HPGe gamma detector

Search for double $\beta$ decay of $^{136}$Ce and $^{138}$Ce was realized with 732 g of deeply purified cerium oxide sample measured over 1900 h with the help of an ultra-low background HPGe $\gamma$ detector with a volume of 465 cm$^3$ at the STELLA facility of the Gran Sasso National Laboratories of the INFN (Italy). New improved half-life limits on double beta processes in the cerium isotopes were set at the level of $\lim T_{1/2}\sim 10^{17}-10^{18}$~yr; many of them are even two orders of magnitude larger than the best previous results.Comment: 21 pages, 6 figures, 3 tables; version accepted for publication on Nucl. Phys.

New limits on 2ε2\varepsilon, εβ+\varepsilon\beta^+ and 2β+2\beta^+ decay of 136^{136}Ce and 138^{138}Ce with deeply purified cerium sample

A search for double electron capture ($2\varepsilon$), electron capture with positron emission ($\varepsilon\beta^+$), and double positron emission $2\beta^+$) in $^{136}$Ce and $^{138}$Ce was realized with a 465 cm$^3$ ultra-low background HP Ge $\gamma$ spectrometer over 2299 h at the Gran Sasso underground laboratory. A 627 g sample of cerium oxide deeply purified by liquid-liquid extraction method was used as a source of $\gamma$ quanta expected in double $\beta$ decay of the cerium isotopes. New improved half-life limits were set on different modes and channels of double $\beta$ decay of $^{136}$Ce and $^{138}$Ce at the level of $T_{1/2}>10^{17}-10^{18}$ yr.Comment: 19 pages, 6 figures, 2 table

Особливості перебігу окиснювальних процесів у щурів, уражених тетрахлорометаном на тлі інтоксикації карбофосом

Topicality. The problem of the environment chemical pollution impact on the human body is one of the priority and not fully studied. Among the pollutants carbon tetrachloride malathion poses a significant reat – it is a factor of risk for many environmentally dependent diseases. There fore, it is important to study the characteristics and mechanisms of a mentioned xenobiotics combined action on the body .Aim. To investigate the activity of free radical processes and the markers of endogenous intoxication at the conditions of effect on the rats organism by tetrachloride on the background of malathion.Materials and methods. While carrying out an experiment white rats were intoxicated by carbon tetrachloride intoxication (4th, 7th days of the affection) in a period of thirty days malathion affection. Rats were taken out of the experiment by the thiopental anesthesia.Results and discussion. The experimental data proved the malathion and carbontetrachloride toxic effect, which increases the conditions of their combined using. Conclusions. It was established, that the maximum activation of free radical processes and deepening endogenous intoxication observed on the seventh day affection by carbontetrachloride in a period of thirty days malathion intoxication.Актуальность. Проблема влияния химического загрязнения окружающей среды на организм человека является одной из приоритетных и до конца не изученных. Среди загрязнителей большую угрозу представляют тетрахлорметан и карбофос – факторы риска многих экологически зависимых болезней. Поэтому изучение особенностей и механизмов комбинированного влияния вышеупомянутых ксенобиотиков на организм есть актуальным. Целью работы было изучить активность свободнорадикальных процессов и маркеры эндогенной интоксикации при воздействии на организм крыс тетрахлорметана и карбофоса. Материалы и методы. Эксперименты проведены на белых крысах, которые подвергались интоксикации тетрахлорметаном (4-ые, 7-е сутки поражения) на фоне тридцатидневного поражения карбофосом. Крыс выводили из эксперимента под тиопенталовым наркозом.Результаты и их обсуждение. Экспериментальные данные подтвердили токсическое влияние карбофоса и тетрахлорметана, которое усиливается при условии их комбинированного применения. Это подтверждается активацией свободнорадикальных процессов и углублением эндогенной интоксикации, максимальное развитие которой наблюдалось на седьмые сутки поражения тетрахлорметаном на фоне тридцатидневной интоксикации карбофосом.Выводы. Доказано, что максимальная активация свободнорадикальных процессов и углубление эндогенной интоксикации наблюдались на седьмые сутки поражения тетрахлорметаном на фоне тридцатидневной интоксикации карбофосом. Актуальність. Проблема впливу хімічного забруднення навколишнього cередовища на організм людини є однією з пріоритетних та не до кінця вивчених. Серед забруднювачів значну загрозу становлять тетрахлорометан та карбофос – фактори ризику багатьох екологічнозалежних хвороб. Тому вивчення особливостей та механізмів комбінованої дії вищевказаних ксенобіотиків на організм є актуальним.Метою роботи було дослідити активність вільнорадикальних процесів та маркери ендогенної інтоксикації за умов впливу на організм щурів тетрахлорометану на тлі ураження карбофосом.Матеріали та методи. Експерименти проведені на білих щурах, які піддавались інтоксикації тетрахлорометаном (4-та, 7-а доба ураження) на тлі тридцятиденного ураження карбофосом. Щурів виводили з експерименту під тіопенталовим наркозом. Результати та їх обговорення. Експериментальні дані підтвердили токсичний вплив карбофосу та тетрахлорометану, який підвищується за умов їх комбінованого застосування. Висновки. Встановлено, що максимальна активація вільнорадикальних процесів та поглиблення ендогенної інтоксикації спостерігається на сьому добу ураження тетрахлорометаном на тлі тридцятиденної інтоксикації карбофосом

Comparative assessment of various methods of miscarriage treatment efficacy in multifetal pregnancy

Aim. Comparative assessment of various methods of miscarriage treatment efficacy in multifetal pregnancy taking into account the cervical remodeling. Materials and Methods. 62 pregnant women with dichorionic twins were observed. The general, somatic, obstetric-gynecological anamnesis, the pregnancy and childbirth course and the state of newborns were studied. All women underwent transvaginal cervicometry throughout the pregnancy. The cervical length and the shape of internal cervical os were determined. Results. In women with uncomplicated pregnancy cervical length was shortened from 43.2 ± 3.9 mm to 38.2 ± 4.0 mm up to 20 weeks’ gestation, from 37.7 ± 4.1 mm to 30.2 ± 3.9 mm up to 30 weeks and to 21.1 ± 3.1 mm up to 37 weeks. In the period of 25–27 weeks V-shaped endocervical canal opening was observed in half of the women and remained until the end of gestation. Cervix shortening was most pronounced in patients with pregnancy threatening miscarriage, who received only tocolytic therapy. In the 2nd trimester V- or U-shaped endocervical canal opening was observed. At 34–36 weeks the length of cervix was significantly shorter than in uncomplicated pregnancy. The rate of cervical length shortening among pregnant women of the risk group, who were treated with a vaginal pessary, and women with uncomplicated pregnancy was similar. The cervical remodeling with a vaginal pessary was not significantly different from that in normal course of multifetal pregnancy before childbirth. In addition, there were no significant differences in the characteristics of delivery, the perinatal mortality indicators and the newborns state. Conclusions. In pregnant women with uncomplicated multifetal pregnancy cervical length shortening is observed as the gestational age increases. In pregnant women with pregnancy threatening miscarriage, who received tocolytic therapy, the cervix was the most shortened. V- and U-shaped endocervical canal changes were observed in the late gestation. Changes in the cervix after vaginal pessary placement are similar to those in uncomplicated pregnancy